Is it cold in Korea during summer?
The climate of the Republic of Korea is cold but sunny in winter, while it's hot and sultry, with abundant rainfall, in summer.
Can you wear leggings in Korea?
So, yes, leggings can be worn anywhere in Korea, including mountains.
What is appropriate to wear in Korea?
Pack fairly conservative clothing. You don't need to cover every inch of skin, but don't expose your cleavage or wear mini skirts. In general, pack clothing you'd be comfortable wearing to a dressy dinner out. In large cities like Seoul, Koreans tend to dress up; you'll stand out in jeans and T-shirts.
Seoul has a wet and very humid climate during the summer season, with cold and dry weather during the winter season. Siberian winds bring frosty weather with sporadic snowfall in the city, which takes the average temperature down to 0 to -10 degrees Celsius.